Electrically actuated locking mechanism



Aug. 22, 1967 I. PARSONS Q 3,336,770

I IELECTRICALIQY ACTUA-TED LOCKING MECHANISM I Filed Jan. '15, 1965 2 Sheets-Sheet 1 Ila Ila-1&2!

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INVENTOR. DALE L. PARSONS BY ATTORNEYS 2,196? D.L, PARS,ONS 3,336,770

- Y 2 Sheets- Sheet 2 Filed Jan. 15. 1965 Y INVENTOR. DALE L. PARSONS ATTORNEYS United States Patent 3,336,770 ELECTRICALLY ACTUATED LOCKING MECHANISM Dale L. Parsons, 355 Serrano Drive,

San Francisco, Calif. 94132 Filed Jan. 15, 1965, Ser. No. 425,706 7 Claims. (Cl. 70-141) This invention relates to an electrically actuated looking mechanism. More particularly it relates to a mechanism that is mechanically pick-proof. It discriminates among various current patterns and intensities and responds only to a selected current, which actuates a solenoid and unlocks the mechanism.

Today a great quantity of money is deposited in parking meters and the quantity is increasing as more municipalities resort to them for revenue. Because the parking meter is exposed without protection, it is an attractive source of money for street derelicts. It has been estimated that various larger cities in the United States lose roughly thirty to fifty thousand dollars annually to parking meter thieves, and it is common in some cities to have forged parking meter keys in circulation among street derelicts which eliminates the need for even picking the lock. It is therefore highly desirable to provide a mechanism for parking meters which is pick-proof and is actuated by a key that cannot be easily duplicated. The lock must be safe, quickly actuated by proper individuals, easily and quickly reset, and resistant to exposure to the elements.

Accordingly, it is an object of the present invention to provide an electrically actuated, mechanically pick-proof locking mechanism that discriminates among current patterns and intensities.

It is a further object to provide a lock that is easily and quickly disengaged or unlocked with the proper current pattern and easily reset or reeng aged.

It is another object to provide a lock which can be simply recalibrated with respect to its electrical discrimination and response.

It is a further object to provide a lock that is resistant to and not damaged by exposure to the elements.

The invention is best described with reference to the drawings wherein:

FIG. 1 is a sectional view taken on the longitudinal aXis of the lock mechanism showing the lock in an engaged or locked position;

FIG. 2 is a sectional view corresponding to the view of FIG. 1 showing the lock in a disengaged or unlocked position;

FIG. 3 is a front view of a parking meter showing the mounting of the lock therein; l

FIG. 4 is a sectional view taken on the line 4-4 of FIG. 1;

FIG. 5 is a sectional view taken on the line 55 of FIG. 1;

FIG. 6 is a sectional view taken on the line 6-6 of FIG. 1 and shows the discriminating printed circuit and its seating.

The invention will be hereinafter described with respect to utilization in a parking meter. It will be readily understood, however, that the invention may be used in a number of other environments. It may be used, for example, as a safe lock; a car, house or garage door lock; or a warehouse lock. Many other uses may be apparent to those skilled in the art.

A specific embodiment is shown in FIGS. 1-6 and the locking mechanism is referred to generally by the numeral 10. It includes lock barrel 11 which defines conical entry cavity 12, O ring recess 13, printed circuit recess 14, retainer ring recess 15, and cylinder 16, which are all axially positioned. Lock barrel -11 also defines latch pin cylinder 17, which is positioned transverse to and communicates with cylinder 16. Latch pin cylinder 17 extends the diameter of lock barrel 11. Solenoid socket 18 is provided above cylinder 16 and communicates therewith through solenoid pin aperture 19. Lock barrel 11 is threaded for engagement with hexagonal nut 20 which may be drawn toward head portion 11a for mounting. Plane faces 11b and are provided to prevent axial rotation of lock barrel 11.

Latch pin cylinder 17 is threaded at one end for engagement with latch pin spring retainer 21. The opposite end defines latch pin cylinder recess 22.

Lock piston 23 is designed with conical head 23a, neck portion 23b, and piston head 23c. Piston head 230 is machined for slidable movement in cylinder 16 and defines piston ring recess 24. Piston ring 25 seated thereon establishes a slidable sealed contact with cylinder 16.

Retainer ring 49 is seated in retainer ring recess 15 and extends inwardly of cylinder 16 substantially to neck portion 23b. Retainer ring 49 therefore limits the withdrawal of lock piston 23 to the position shown in FIG. 2 by preventing the passage therethrough of piston head 23c. Lock piston 23 is therefore slidable in cylinder 16 for a stroke which is apparent by comparing FIG. 1 with FIG. 2.

Entry cone ring 50 seals the joint between conical entry cavity 12 and conical head 23a, thereby preventing damage due, for example, to the entry of water and subsequent freezing or entry of dirt.

Latch pin piston 27 is machined for slidable movement in latch pin cylinder 17 and contains latch pin ring 28 seated in latch pin piston recess 29. An eflicient seal is therefore provided between latch pin piston 27 and its cylinder 17. Latch pin cylinder ring 30, seated in latch pin cylinder recess 22, provides an additional seal but is not essential. Latch pin piston 27 contains spring connector arm 31. Latch pin piston 27 is slidable in latch pin cylinder 17 for a stroke that is apparent by comparing FIG. 1 with FIG. 2.

Lat-ch pin spring retainer 21 is threaded into latch pin cylinder 17 and contains latch pin spring connector arm 32. Latch pin spring 33 extends from connector arm 31 to connector arm 32 and is under tension.

Cylinder 16 in communication with latch pin cylinder 17 and in conjunction with piston head 23c, latch pin piston 27 and latch pin spring retainer 21, defines oil reservoir 34. Oil reservoir 34 is completely filled with oil =(S.A.E. 10, for example).

Solenoid 35 is seated in solenoid socket 18 with solenoid pin 36 extending through solenoid pin aperture 19. Solenoid pin 36 has a stroke actuated by an electromotive force in the range of 6128 volts. At the end of the downward stroke, which is actuated by solenoid spring 37, solenoid pin 36 contacts the neck portion 23b to prevent withdrawal of lock piston 23 as shown in FIG. 1. At the end of its upward stroke, which is the response to electromagnetic force, solenoid pin 36 releases piston head 23c and allows the withdrawal of lock piston 23 as shown in FIG. 2.

Solenoid leads 38 extend from solenoid 35 to printed circuit output contacts 39 in printed circuit recess 14. Printed circuit input contacts 40 are provided in recess 14 as shown in FIG. 6 and are connected by leads 41 to exposed contacts 42. Thus, the proper current applied to exposed contacts 42 finds its way through printed circuit 43 to solenoid 35 to withdraw solenoid pin 36.

Locking mechanism 10 is mounted in a door 44 through aperture 45 with the aid of hexagonal nut 20. FIG. 3 shows the mounting of the locking mechanism 10 in a parking meter door.

Stationary latch socket 46 is rigidly secured in a position such that it accepts latch pin piston 27 when the 3 latter is at the upper limit of its stroke as shown in FIG. 1. At the lower limit of its stroke, as shown in FIG. 2, latch pin piston 27 is removed from socket 46, and is slidable past socket 46.

Having thus described the structure of the lock mechanism, its operation may be best understood with reference to FIG. 1, which shows the relative position of the various elements when the mechanism is locked or engaged, and to FIG. 2, which shows the relative position of the elements when the mechanism is unlocked or disengaged.

In the locked or engaged position latch pin piston 27 is engaged with latch socket 46 and movement of door 44 with respect to socket 46 is prevented. In other words, the meter is locked because door 44 is not pivotable about hinge 47.

The meter is opened by contacting exposed contacts 42 with the leads from a source of current that will bridge printed circuit 43. Solenoid 35 is then actuated and pin 36 is withdrawn as shown in FIG. 2. Lock piston 23 may then be withdrawn. The withdrawal is actuated by latch pin spring 33 which slides latch pin piston 27 out of engagement with socket 46. Oil reservoir 34, free to expand in cylinder 16, shifts to make room for latch pin piston 27. Thus, the elements assume the relative position shown in FIG. 2.

The locking mechanism may be simply and quickly reset by removing the current, closing the door, and then manually pressing lock piston 23 into cylinder 16. Latch pin piston 27 is then forced upwardly and engages socket 46 and the meter is locked.

In the event it is not desired to use an oil reservoir as the means of linking lock piston 23 and latch pin piston 27, a mechanical linkage could be employed. An oil reservoir is preferred, however, because it makes the position of latch pin piston 27 very flexible with respect to lock piston 23. It also eliminates the need for intricate universal and other joints necessary in a mechanical linkage. It is readily recognized, however, that a mechanical linkage could be employed within the scope of the present invention.

The locking mechanism may be simply and quickly recalibrated by removing the printed circuit and replacing it with another one which responds to a different current pattern and intensity. Such circuits, referred to generally as flip-flop circuits, may be readily designed by those skilled in the art and employed in combination with the present invention. For convenience of replacement the printed circuit is mounted on a disc 47 which may be readily slipped into printed circuit recess 14 and removed therefrom.

Having thus described my invention, I claim:

1. A locking mechanism which comprises:

(A) a lock barrel defining (1) a first cavity having a longitudinal axis,

(2) a second cavity transverse to said first cavity and in communication therewith, and

(3) a solenoid socket and pin aperture, said pin aperture communicating with said socket and first cavity;

(B) an exposed locking member axially slidable in said first cavity;

(C) a latch pin slidable beyond the surface of said lock barrel in said second cavity;

(D) means for linking said locking member and said latch pin such that Sliding motion in one produces a corresponding sliding motion in the other;

(E) a solenoid in said solenoid socket having a pin extending through said pin aperture, said pin, when extended, engaging said locking member and preventing sliding movement thereof; and, when withdrawn, disengaging said locking member and allowing sliding movement thereof.

2. The locking mechanism of claim 1 wherein said 4 lock barrel has exposed contacts and a discriminatory circuit linking said contacts and said solenoid.

3. A locking mechanism which comprises:

(A) a lock barrel defining (1) a first cavity having a longitudinal axis,

(2) a second cavity transverse to said first cavity and in communication therewith, and

(3) a solenoid socket and pin aperture, said pin aperture communicating with said socket and first cavity;

(B) an exposed lock piston axially and sealingly slidable in said first cavity;

(C) a latch pin piston sealingly slidable beyond the surface of said lock barrel in said second cavity; (D) an oil reservoir in said first and second cavities in contact with said lock piston and said latch pin piston;

(E) oil completely filling the reservoir;

(F) a solenoid in said solenoid socket having a pin extending through said pin aperture, said pin, when extended, engaging said lock piston and preventing sliding movement thereof; and, when withdrawn, disengaging said lock piston and allowing sliding movement thereof;

(G) means for urging the latch pin piston inwardly of the surface of the lock barrel;

(H) means for limiting the sliding movement of the exposed lock piston outwardly of the surface of the lock barrel; and

(I) keeper means adapted to be engaged with and disengaged from the latch pin piston as said latch pin piston slides relative to the lock barrel.

4. The locking mechanism of claim 3 wherein said lock barrel has exposed contacts and a discriminatory circuit linking said contacts and said solenoid.

5. A locking mechanism which comprises: (A) a lock barrel defining (1) a first cavity having a longitudinal axis, (2) a second cavity transverse to said first cavity and in communication therewith, and (3) a solenoid socket and pin aperture, said pin aperture communicating with said socket and first cavity;

(B) an exposed lock piston axially slidable in said first cavity;

(C) a latch pin piston slidable beyond the surface of said lock barrel in said second cavity;

(D) a hermetically sealed chamber defined by said lock piston, said first cavity, said second cavity and said latch pin piston;

(E) a fluid completely filling the chamber;

(F) a solenoid in said solenoid socket having a pin extending through said pin aperture, said pin when extended engaging said lock piston and preventing sliding movement thereof; and, when withdrawn, disengagin said lock piston and allowing sliding movement thereof;

(G) means for urging the latch pin piston inwardly of the surface of the lock barrel;

(H) means for limiting the sliding movement of the exposed lock piston outwardly of the surface of the lock barrel; and

(I) keeper means adapted to be engaged with and disengaged from the latch pin piston as said latch pin piston slides relative to the lock barrel.

6. The locking mechanism of claim 5 wherein oil is the fluid in said hermetically sealed chamber.

7. A locking mechanism which comprises:

(A) a lock barrel defining (1) a first cylinder having a longitudinal axis, (2) a second cylinder transverse to said first cylinder and in communication therewith, and (3) a solenoid socket and pin aperture, said pin aperture communicating with said socket and said first cylinder;

(B) an exposed lock piston axially slidable in said first cylinder, said piston having a piston head and a neck portion;

(C) a latch pin piston slidable beyond the surface of said lock barrel in said second cylinder;

(D) a hermetically sealed chamber defined by said lock piston head, said first cylinder, said second cylinder, and said lock pin piston;

(E) oil completely filling said chamber in contact with said piston head and said latch pin piston;

(F) a solenoid in said solenoid socket having a pin extending through said pin aperture, said pin when extended, engaging said neck portion and preventing the slidingrnovement of said piston head in said first cylinder, and, when withdrawn, disengaging said neck portion and allowing sliding movement of said piston head in said first cylinder;

(G) means for urging the latch pin piston inwardly of the surface of the lock barrel;

(H) means for retaining said piston head in said first cylinder;

(I) exposed contacts on said lock barrel;

(J) a discriminatory circuit linking said contacts and said solenoid; and

(K) keeper means adapted to be engaged with and disengaged from the latch pin piston as said latch pin piston slides relative to the lock barrel.

References Cited UNITED STATES PATENTS 2,103,702 12/1937 Tibbetts 70-283 2,765,648 10/ 1956 Hatchet 70-283 X FOREIGN PATENTS 1,067,742 1 1/ 1954 France.

16,353 4/ 1898 Great Britain.

BOBBY R. GAY, Primary Examiner. 

1. A LOCKING MECHANISM WHICH COMPRISES: (A) A LOCK BARREL DEFINING (1) A FIRST CAVITY HAVING A LONGITUDINAL AXIS, (2) A SECOND CAVITY TRANSVERSE TO SAID FIRST CAVITY AND IN COMMUNICATION THEREWITH, AND (3) A SOLENOID SOCKET AND PIN APERTURE, SAID PIN APERTURE COMMUNICATING WITH SAID SOCKET AND FIRST CAVITY; (B) AN EXPOSED LOCKING MEMBER AXIALLY SLIDABLE IN SAID FIRST CAVITY; (C) A LATCH PIN SLIDABLE BEYOND THE SURFACE OF SAID LOCK BARREL IN SAID SECOND CAVITY; 